The GPR40 range of interference measuring radio receivers were developed by a British company, Chase Electronics, based (when I joined them at least) in a two storey industrial building, St. Leonards House, close to Mortlake railway station in East Sheen, South London.

The GPR40 was a highly specialised device, each of which was hand built, with a list price of around £10,000 in 1986.

At some point the rights to the devices was sold to a German company, Willtek Communications GmbH.

I am aware of the following models, please use the contact page if you can add any more information to the list!


Presumably this existed as at least a prototype but it was before my time

GPR40.2 / Willtek 8100

This is the version that I worked on. At some point the rights appear to have been sold to Willtek GmbH of Ismaning, Germany.

Flyers and Manuals

Chase original Flyer / Specification Sheet

Will’Tek Flyer / Specification Sheet

Will’Tek Down Convertor Flyer / Specification Sheet

Will’Tek Getting Started Manual (for serial numbers 0506001 and higher) – copyright dated 2003

Will’Tek Getting Started Manual – copyright dated 2002 – 2007

Will’Tek User’s Guide Version 4.00 – copyright dated 2007

Circuit Diagrams & Construction Drawings

[In progress, some of these need a bit of image cleaning and I’m trying to get them into some kind of order]